The present invention relates to a circuit arrangement for amplifying high frequency electromagnetic waves through the use of at least two weakly coupled superconductors arranged to form a Josephson junction which receives pumping energy from a direct voltage applied to the two superconductors.
A weakly coupled superconductor or Josephson junction is an arrangement of two superconductors which are separated by a thin tunnel layer of insulating material, or are connected together by a peak contact, an extremely narrow conductive bridge or in some other way.